From: Peter Rosin <peda@axentia.se> To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Cc: Peter Rosin <peda@axentia.se>, Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>, Tomi Valkeinen <tomi.valkeinen@ti.com>, Fabian Frederick <ffrederick@users.sourceforge.net>, Geert Uytterhoeven <geert+renesas@glider.be>, Geoff Levand <geoff@infradead.org>, James Simmons <jsimmons@users.sf.net>, "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>, "linux-fbdev@vger.kernel.org" <linux-fbdev@vger.kernel.org> Subject: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs Date: Thu, 8 Nov 2018 09:54:28 +0000 [thread overview] Message-ID: <20181108095347.19326-1-peda@axentia.se> (raw) Blitting an image with "negative" offsets is not working since there is no clipping. It hopefully just crashes. For the bootup logo, there is protection so that blitting does not happen as the image is drawn further and further to the right (ROTATE_UR) or further and further down (ROTATE_CW). There is however no protection when drawing in the opposite directions (ROTATE_UD and ROTATE_CCW). Add back this protection. The regression is 20-odd years old but the mindless warning-killing mentality displayed in commit 34bdb666f4b2 ("fbdev: fbmem: remove positive test on unsigned values") is also to blame, methinks. Fixes: 448d479747b8 ("fbdev: fb_do_show_logo() updates") Signed-off-by: Peter Rosin <peda@axentia.se> --- drivers/video/fbdev/core/fbmem.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index bb7f5f23e347..1abeb0b72455 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -435,7 +435,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image, image->dx += image->width + 8; } } else if (rotate == FB_ROTATE_UD) { - for (x = 0; x < num; x++) { + u32 dx = image->dx; + + for (x = 0; x < num && image->dx <= dx; x++) { info->fbops->fb_imageblit(info, image); image->dx -= image->width + 8; } @@ -447,7 +449,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image, image->dy += image->height + 8; } } else if (rotate == FB_ROTATE_CCW) { - for (x = 0; x < num; x++) { + u32 dy = image->dy; + + for (x = 0; x < num && image->dy <= dy; x++) { info->fbops->fb_imageblit(info, image); image->dy -= image->height + 8; } -- 2.11.0
WARNING: multiple messages have this Message-ID (diff)
From: Peter Rosin <peda@axentia.se> To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Cc: Peter Rosin <peda@axentia.se>, Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>, Tomi Valkeinen <tomi.valkeinen@ti.com>, Fabian Frederick <ffrederick@users.sourceforge.net>, Geert Uytterhoeven <geert+renesas@glider.be>, Geoff Levand <geoff@infradead.org>, James Simmons <jsimmons@users.sf.net>, "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>, "linux-fbdev@vger.kernel.org" <linux-fbdev@vger.kernel.org> Subject: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs Date: Thu, 08 Nov 2018 09:54:28 +0000 [thread overview] Message-ID: <20181108095347.19326-1-peda@axentia.se> (raw) Blitting an image with "negative" offsets is not working since there is no clipping. It hopefully just crashes. For the bootup logo, there is protection so that blitting does not happen as the image is drawn further and further to the right (ROTATE_UR) or further and further down (ROTATE_CW). There is however no protection when drawing in the opposite directions (ROTATE_UD and ROTATE_CCW). Add back this protection. The regression is 20-odd years old but the mindless warning-killing mentality displayed in commit 34bdb666f4b2 ("fbdev: fbmem: remove positive test on unsigned values") is also to blame, methinks. Fixes: 448d479747b8 ("fbdev: fb_do_show_logo() updates") Signed-off-by: Peter Rosin <peda@axentia.se> --- drivers/video/fbdev/core/fbmem.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index bb7f5f23e347..1abeb0b72455 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -435,7 +435,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image, image->dx += image->width + 8; } } else if (rotate == FB_ROTATE_UD) { - for (x = 0; x < num; x++) { + u32 dx = image->dx; + + for (x = 0; x < num && image->dx <= dx; x++) { info->fbops->fb_imageblit(info, image); image->dx -= image->width + 8; } @@ -447,7 +449,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image, image->dy += image->height + 8; } } else if (rotate == FB_ROTATE_CCW) { - for (x = 0; x < num; x++) { + u32 dy = image->dy; + + for (x = 0; x < num && image->dy <= dy; x++) { info->fbops->fb_imageblit(info, image); image->dy -= image->height + 8; } -- 2.11.0
next reply other threads:[~2018-11-08 9:54 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-11-08 9:54 Peter Rosin [this message] 2018-11-08 9:54 ` [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs Peter Rosin 2018-11-26 14:16 ` Peter Rosin 2018-11-26 14:16 ` Peter Rosin 2018-11-26 14:33 ` Bartlomiej Zolnierkiewicz 2018-11-26 14:33 ` Bartlomiej Zolnierkiewicz 2018-11-26 21:19 ` Peter Rosin 2018-11-26 21:19 ` Peter Rosin 2018-12-20 16:49 ` Bartlomiej Zolnierkiewicz 2018-12-20 16:49 ` Bartlomiej Zolnierkiewicz
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